Hypothyroidism, or low thyroid function, is common among people suffering from chronic fatigue syndrome (ME/CFS)1 and fibromyalgia2 and is likely a concern in other related conditions.
The thyroid can be seen as the body's accelerator pedal - regulating the rate of metabolism of all cells. Symptoms of hypothyroidism include:
- Weight Gain
- Low Body Temperature
- Poor Memory
- Poor Mental Focus
- Slowed Thinking
- Skin Conditions - Typically Dry, Coarse and Thickened
- Hair Loss - General Hair Loss Plus Characteristic Loss of Outer Third of Eyebrows
- High Cholesterol
According to researchers there could be any number of reasons why thyroid hormone is either not being produced in sufficient amounts or is not functioning correctly in ME/CFS, fibromyalgia and other environmental illnesses. These include:
- Hypothalamic & Pituitary Dysfunction - These 'master' glands produce inadequate amounts of hormones signalling the thyroid gland to increase production of thyroid hormones1.
- CRH Dysfunction- CRH is a hormone produced by the hypothalamus in response to stress and activates the stress (fight-or-flight) reponse. In ME/CFS and fibromyalgia response to CRH and the stress response are abnormal with one end result being that the production of thyroid hormones is disrupted3.
- Autoimmune Thyroiditis - The immune system attacks the thyroid gland with antibodies interfering with its ability to produce thyroid hormones2.
- Conversion Failure - The thyroid produces two major hormones thyroxine (T4) and triidothyronine (T3). T4 is considered the storage form and T3 the active hormone. Those who are chronically ill may have trouble converting T4 to T3 due to deficiencies of selenium and other nutrients essential to the conversion process.
- Thyroid Hormone Transport - There may be problems with the transport of thyroid hormones into the cells4.
- Intracellular Metabolism - Once in the cell the thyroid hormone may not be handled correctly4.
- Receptor Binding and Resistance - For hormones to transfer their message to cells they must bind to receptors. In chronic illness the hormones may not bind properly to the receptors and if they do the receptor itself may not function correctly and not pass on the message4.
- Nutritional Deficiencies - Various nutrients are integral to the production and function of thyroid hormones.
In addition, many toxins have been identified that can block the action of thyroid hormones4. Those suffering from ME/CFS , fibromyalgia and other environmental illnesses are known to carry an increased toxic load (heavy metals, microbial toxins, environmental pollutants such as PCBs etc), have increased oxidative stress, and low levels of the antioxidants such as glutathione required to deal with all of this. These factors may all interfere with the function of thyroid hormones and result in hypothyroid symptoms.
Environmental Toxins that Impair Thyroid Function
Dioxins - Highly toxic chemicals that interfere with the uptake of iodine and its processing into thyroid hormones. Produced in combustive processes, they have historically been produced in large amounts by heavy industries with diesel trucks being another source. Though measures have been taken in developed nations to limit their production the UK's Food Standards Agency (FSA) reports that they are still present in all foods.
Polychlorinated Biphenyls (PCBs) - Affect thyroid function in the same way as dioxins. Both types of chemical also remain in fatty tissues of the body for many years. PCBs used to be used in many electrical goods and have also been used in products such as plasticizers, surface coatings, inks, adhesives, flame-retardants, and paints. Again, their use has been phased out but substantial amounts remain in the environment and the food chain.
Heavy Metals - Block the uptake and use of selenium to convert T4 to T3. These include mercury, lead and cadmium which are produced by industry, contaminate the food chain (especially fish - mercury) and are found in cigarette smoke and some vaccines.
Fluoride - Blocks iodine uptake and damages enzymes involved in thyroid hormone production and function. It also upregulates a cell protein called Gq/11 which desensitizes the thyroid to stimulation by thyroid-stimulating hormone (TSH) resulting in reduced production of thyroid hormones. Gq/11 also blocks the action of T3 within the cells. Fluoride is found in some municipal water supplies, most toothpastes, and also in tea since the plant takes up a lot of fluoride from the soil.
Aluminium, Silica, Beryllium - All activate the Gq11 protein.
Natural Treatments for Low Thyroid Function
Diet and Lifestyle
Believe it or not a number of common foods which are usually considered healthy and nutritious interfere with thyroid function. The main ones being:
Brassicas (Cabbage, Broccoli, Cauliflower etc) - Contain a compound called thiouracil which blocks thyroid hormone production. Cooking reduces the potency of this compound but brassica consumption should be limited in hypothyroidism.
Soy - Contains phytoesterogens which mimic the body's own oestrogen. Both phytoesterogens from soy and the body's own hormone block the action of thyroid hormone.
Tea - Contains high amounts of fluoride which block iodine uptake.
Other foods that should be avoided - Turnips, cassava, pine nuts, mustard, peanuts, millet
Alcohol and caffeine should also be avoided as they impair liver function and deplete the body of nutrients vital to thyroid function. Smoking should certainly be avoided as it tobacco smoke contains a huge range of toxins including dioxins and heavy metals whose effects on thyroid function we have already seen.
Dieting is not a good idea in hypothyroidism as this only causes the thyroid to reduce production of hormones even further to conserve energy. When hypothyroidism is treated properly it will be much easier to lose weight anyway, especially with regular exercises which increases thyroid activity.
About 150mcg of iodine per day is required for proper thyroid function as it is a component of thyroid hormones. The number in the name of each thyroid hormone indicates the number of iodine atoms it contains i.e. T3 has three atoms of iodine while T4 has four. Deficiency of iodine causes the thyroid gland to enlarge into what is known as a goitre and results in symptoms of hypothyroidism because the thyroid is unable to manufacture thyroid hormones. Good food sources of iodine include fish, seafood and sea vegetables as well as Yoghurt, cow's milk, eggs, mozzarella cheese and strawberries - particularly where soial content is high and animal feed is fortified. Iodine supplements are also available, usually as kelp extracts.
An amino acid which like iodine is a component of thyroid hormones and is therefore essential to their production. Food sources of tyrosine include fish, chicken, pork, wheat, oats, dairy products, avocados, bananas, lima beans, almonds, sesame seeds and pumpkin seeds. Tyrosine supplements are widely available in tablet, capsule and powdered form. Individuals particularly at risk of tyrosine deficiency are those who have a metabolic disorder known as phenylketonuria. This condition means the body cannot utilise phenylalanine properly. Phenylalanine is another amino acid from which tyrosine is made in the body.
This trace mineral is another essential nutrient in the process of thyroid function. It is required to make the enzyme 5-deionidase which converts T4 to T3. Food sources include grains (eg. corn, wheat, oats, and rice), nuts (brazil nuts and walnuts), fish (tuna) and meat and dairy products (beef, chicken, egg, cheese).
Controls the uptake of Iodine into the thyroid gland. Deficiency also reduces production of thyroid-stimulating hormone (TSH) by the pituitary gland. Conversion of beta-carotene to vitamin A is inhibited by low thyroid states, and may cause yellowing of the skin.
Vitamin B complex is required for proper thyroid function. In particular B1 (thiamin), B2 (riboflavin) and B6 (pyridoxine) are important for the manufacture of thyroid hormones and their uptake at the cells. Deficiency of B vitamins results in the cells becoming intolerant to thyroid hormones meaning they can't do their job increasing metabolism.
Vitamins C & E
Deficiency has been shown to cause hyperplasia of the thyroid (also known as goitre or goiter). This is what also occurs with iodine deficiency and is an enlargement of the thyroid which leads to a decrease in hormone output.
This mineral is involved in huge numbers of enzymatic reactions in the body, particularly those involving other minerals. Research suggests it is important for thyroid function at every level including T4 to T3 coversion and the intracelluar action of T3.
Other nutrients involved with maintaining healthy thyroid function include magnesium, calcium, manganese, iron, and boron.
A herb native to subtropical areas of India, Thailand and Burma. It is widely used in Ayurvedic medicine. Its active constituent Forskolin has been shown to increase the production of thyroid hormones and stimulate their release5. It also increases an important chemical called Cyclic AMP which is involved in making sure the thyroid hormone message is transmitted to the nucleus of the cell6.
Guggul (Commiphora mukul)
Another ayurvedic herb with particular benefits in hypothyroidism. Research in mice shows that the active constituents (guggulsterones) have strong thyroid stimulating actions and increase iodine uptake7. Guggul has also been shown to improve liver function and reduce lipid peroxidation (damage to fats by free radicals). One study found that guggulsterones simultaneously increase T3 while lowering lipid peroxidation. It is therefore concluded that since the liver is the major site of conversion of T4 to T3 guggul increases T3 levels by protecting the liver from free radicals and improving liver function8.
Yet another herb traditionally used in ayurvedic medicine is ashwagandha. It works in a similar way to guggul in improving thyroid function by increasing blood levels of T4 and T3 as well as reducing lipid peroxidation in the liver and increasing antioxidants such as superoxide dismutase and catalase9.
Adrenal fatigue and hypothyroidism often go hand in hand with stress causing a rise in CRH and cortisol levels which suppress thyroid function. If the stress continues cortisol remains raised and compensates for less thyroid hormone but eventually the adrenal glands cannot sustain this level of cortisol output and adrenal fatigue results.
Experts such as Dr. Barry Durrant-Peatfield, author of 'Your Thyroid and How to Keep it Healthy', recommend treating both underactive adrenal and thyroid glands at the same time.
See our Adrenal Fatigue page for information on how to treat this problem.
Imbalances in sex hormones (oestrogen, progesterone, testosterone) can also interfere with thyroid function so it is important to work with your doctor to make sure your levels are optimal.